The general type of the reaction is already known from DE-B 21 36 496; it is generally carried out in the presence of organic peroxides (e.g. di-tert-butyl peroxide). In this case, the initial charge is for example an excess of cyclododecanone (at least 4 moles per mole of alkene), and to this is added, over the course of 6 hours, a mixture of allyl alcohol and di-tert-butyl peroxide (10-20 mol %, based on alkene) at 140-150.degree. C.
Although, in principle, free-radical reactions of this type take place in a few minutes, with this discontinuous method the allyl alcohol is added very slowly in order to suppress, as far as possible, secondary reactions which lead to polymeric material.
Despite this slow addition, considerable amounts of polymeric byproducts form. A further disadvantage is the poor space-time yield which results because of the long metering time.
The object of the present invention was thus to largely avoid these disadvantages.